1998 Yamaha Exciter Engine and Boat Repair Needed (Local Only-Clarkston, Michigan)

My 1998 Yamaha Exciter 135 will idle at the dock but refuses to move past roughly 5 mph no matter how far the throttle is advanced. After a short run the engine overheated and now won’t stay running at idle either... (Budget: $15 - $25 USD, Jobs: Marine Engineering, Mechanical Engineering, Performance Tuning, Technical Support, Troubleshooting)